We can actually start a discussion out of this.
So let's see, in ActIV of Hanako's route the OP claimed that
"she sure does give up her virginity easily, doesn't she? Not even Emi is as much of a nympho as Hanako is". Frankly, I may disagree on Hanako's take on the situation but I can't bring myself to call her a 'ho' as situations and her psychology
geared her towards that decision. So let's see how the events of the route is laid out that leads to the situation:
-Hanako takes Hisao to her room to bear her scars and show him her full-trust
-Hisao has a healthy adolescent sex drive. He jumped first on to Hanako (ACTIV, Whispered touch--"Her lips are open, just a little. She lets out a sharp breath as, without thinking, I breathlessly lean forwards and press my lips to hers.")
-Post-scene, Hanako admits her fear and take on the event (ACTIV, Adulthood--"I thought...you might eventually go away if I was only someone you needed to protect. I thought that if I let you do that...you might see me as someone more than that.")
I can't help it, but this PSA actually fits:
"Just because she doesn't say 'no', doesn't mean it's a 'yes'. Don't be 'that guy'."
When Hisao walked into class the next day with Hanako, he realize that he has become "that guy".
now anyway, back to the point.
Now we look into Hanako's psyche. As a character, she is well-known as the timid girl that is very much submissive at certain times until you step on that landmine where Dovah-Hanako shows up and 'Fus ro Dah' Hisao. Hanako is--to some degree--identical to Shizune. She wants to make friends but her disability prevented her from doing so, a lone friend that acts as her mediator until specific time, and how she values her friends.
But unlike Shizune, Hanako values trust at a much greater stance, whereas the former places more emphasis on the good of others more than herself.
So when Hisao shows Hanako her scars, she saw it as a sense of 'bond' or 'trust' more than anything--and she feels that it's only fair for her to do the same. This took up a gargantuan amount of courage from her side, and when Hisao jumped the gun she doesn't refuse--rather, her psyche can't refuse. Why? Because of her
fear of
losing someone implemented by her accident when she was eight years old (in Shizune's case, it's her fear of being isolated and left alone). So more than any, her
bad ending destroyed her because she's the one who drove Hisao away, though to be fair it is Hisao's fault in the first place--way to go, hero!
In the end, we ask ourselves if the scene is consensual (or the usual raep-discussion pops up). To that, as awkward as it is, it is consensual as seen at the conclusion of the scene--still, that doesn't mean Hisao isn't wrong in that part. He is the one at fault and became 'that guy', but it was redeemed later in ACTIV, Adulthood when he admits it.
also, "nympho" is basically 'a woman with abnormal sexual desires'. Unless you change its meaning in the dictionary as 'healthy adolescent sex drive', then no it doesn't hold candle to your statement OP.